Projects - Structures
Site Structures: Retaining Walls

63rd Street Retaining Wall
Boulder County, Colorado

Boulder County, Colorado

Boulder County Transportation needed to change the severe vertical and horizontal alignments of 63rd Street just south of Jay Road for safety reasons. This redesign required lowering the roadway grade about 14 feet from its previous location. The challenge was that the roadway is in a pristine, rural portion of the county and the right-of-way is adjacent to City of Boulder Open Space with sensitive plant and prairie dog populations. Roadway modifications needed to be both environmentally and aesthetically sensitive.

LORIS' engineers evaluated several options that would allow for the deep cut while minimizing right-of-way takes and environmental damage. We investigated both retaining walls (MSE, cantilever and soil-nail) and cut-and-cover tunnel options. In the end, a soil-nail retaining wall system was selected to minimize disruption of open space.

Then, to avoid having an obtrusive, stark, 30 foot tall concrete face exposed in this rural location, Loris and Boulder County worked together to develop a contextual wall appearance. We selected an irregular wall surface with jogs and setbacks to provide planting beds. The shotcrete soil-nail wall face was then covered with architectural concrete that is similar in appearance to the nearby Valmont Butte.

The project won the 2002 Award of Excellence for Decorative Concrete from the Rocky Mountain Chapter of the American Concrete Institute.